56 STEPPE FAUNAS AND TEMPERATE 
there are other large areas in Africa and in the north of 
South America where open park-like country occurs, 
with trees scattered among the grass, and such land has 
some of the characters of a steppe. Again, all the great 
deserts of the world are fringed by semi-arid areas, 
displaying the general characters of a steppe. 
The great interest of the steppe areas is that, espe- 
cially in Asia and Africa, they are the natural home of 
very many of the great ungulates, the most highly 
specialized of which are steppe animals. In North 
America the steppe lands, within the human period 
at least, have been inhabited only by few species of 
wild ungulates, but of these few the bison was repre- 
sented by countless numbers of individuals until it 
was exterminated by the white man. In South America, 
within the human period, but prior to the immigration 
of the white, large ungulates were almost absent. No 
horse, no relative of cattle or sheep or antelope cropped 
the herbage of the great plains, but their place in 
nature was taken by enormous numbers of rodents, 
which reached here a size not attained elsewhere. 
Again, in Australia no ungulate whatever occurred, 
and the natural pasture was utilized by marsupials or 
pouched animals, of which the most important grass- 
eating form is the kangaroo. 
That South America has few native ungulates and 
Australia none are two of the most interesting facts in 
geographical distribution, but the fact that ungulates 
introduced by the white man into both countries have 
flourished apace makes it unnecessary for us to suppose 
that any natural obstacle to their presence there 
existed. We may then say generally that the steppe 
regions of the world are the regions which form the 
natural home of the ungulates most valuable to man. 
